ABC News has learned that David Bonior, the campaign manager for the 2008 presidential race of Sen. John Edwards, D-NC, will endorse Sen. Barack Obama, D-Illinois, today.Bonior, a former Michigan congressman, was once the second highest ranking Democrat in the House, and is influential with labor unions.

Tuesday night’s results were said to be key to Bonior’s decision — specifically the fact that Obama’s lead over Sen. Hillary Clinton, D-NY, appears insurmountable.

Bonior is also said to like Obama’s general positive tone, as well as Obama’s message of change and stance against taking money from federal lobbyists.